BEIJING (AP) — China Meteorological Administration says the country’s average temperature has hit the lowest in 28 years this winter, as snow and ice throughout China have closed highways, canceled flights and stranded travelers.

The figures released by the administration on Friday show the national average was -3.8 degrees Celsius (25 degrees Fahrenheit) since late November.

The average temperature in northeast China dipped to -15.3 degrees C (4.5 degrees F), the coldest in 43 years, and dropped to a 42-year low of -7.4 degrees C (18.7 degrees F) in northern China.

The administration says the temperatures are dropping partly because of south-moving polar cold fronts, caused by melting polar ice from global warming. It adds the air is moist and likely to dump heavy snow in China, Europe and North America.